Coil form and the like



Oct. 20, 1942. J. B. SEEVER 2,299,113

COIL FORM AND THE LIKE Filed Dec. 8, 1959 2 Sheets-Sheet 1 Oct. 20,1942- J. B. SEEVER COIL FORM AND THE LIKE Filed Dec. 8, 19:59 2Sheets-Sheet 2 spool or bobbin Patented Oct. 20, 1942 2,299,113 COILFORM AND THE LIKE John B. Seever, Oak Park, 111., asslgnor to William F.Stahl Application December 8, 1939, Serial No. 308,259

4 Claims.

This invention relates to a coil form and the like. It is particularlyuseful as a bobbin or spool for coil windings, although it obviouslywill be applicable to other uses.

An object of the invention is to provide a simple and inexpensivestructure and also an expeditious method for forming the same, thestructure enabling windings to be supported on a light, sturdy form. Afurther object is to provide a method and means forsupporting windings,the form being made of'laminated tape and set in permanent position bysimple and inexpensive steps. Other specific objects and advantages willappear as the specification proceeds.

The invention is illustrated in a preferred em.- bodiment, by theaccompanying drawings, in Which- Figure l is a side view in elevation ofa spool embodying my invention; Fig. 2, an end view in elevation; Fig.3, an enlarged longitudinal sectional view taken on line 3 of Fig. 2;Fig. 4, a side view in elevation of a modified form of the invention;Fig. 5, an end view thereof; Fig. 6, a broken sectional end view of thestructure shown in Figs. 4 and 5 taken on line 6, of Fig. 5; Fig. '7, aside view in elevation of a modified form of embodying my invention;Fig. 8, an end view of the structure shown in Fig. '7; and Fig. 9, adetail sectional view, the section being taken as indicated at line 9 ofFig. 8.

In the illustration given, In designates a tubular core, and H, sideflanges secured to the core.

The core I0 is formed by drawing gummed tape about a mandrel so that theadhesive secures one tape winding to the next and provides a laminatedtubular body. The tape is preferably provided with water-solubleadhesive which is moistened just prior to the winding operation.Preferably a relatively long tube is formed, and this is subsequentlycut into the desired lengths for the coil form.

The flanges l I may be formed of fiber, Bakelite, or any other suitablematerial. They are provided with a central opening adapted to receivethe core body In. In the illustration given, the flanges l l areprovided with an inwardly-turned recess adapted to receive the swagedends of the core.

In'the assembly of spools of this type heretofore, rather extensiveoperations have been followed. I have discovered that the assemblyoperation can be accomplished briefly and with excellent results byfollowing the steps set out below.

After the short length of core I0 has been formed, I place the flangesII in slight separation of the position, snugly receiving the core andnear the ends thereof. The ends of the core are then swaged inwardly toform the upwardly-turned flanges M. The blow of the metal membersstriking the edges l4 anddirecting them upwardly shatters thewater-soluble -adhesive which" is now dry and tends to separate slightlythe tape 7 windings at the edge of the structure. To facilitate-theswaging operation when a rectangular edges so as to form the indicatedmore clearly in core is used, I cut the V-shaped spaces l5, as Fig. 2.

After the structure has been formed with flanges l4 struck upwardly andresting within the recess l2 of flanges H, I immerse the form in asolution of a hardening varnish, lacquer, or condensation product suchas phenol formaldehyde solution. Such products are well known and neednot be described in detail. The layer of varnish or lacquer l6 forms onthe outside of the core l0 and provides a shoulder against the flanges Hwhich under normal circumstances will prevent the flanges from movinginwardly. At the same time, the hardening material penetrates the edgesof the flanges M where the swaging has caused a paper laminations. Thehardening lacquer fills these spaces, with the result that the flanges Mare permanently set in position with the firmness substantially ofmetal. Further, the tendency of the hardening lacquer to form within theV-shaped recesses l5 prevents the flanges M from tending to return totheir original position. Thus, by very few and simple steps, a productis formed which is extremely sturdy and which may be formed atexceedingly low cost. As already stated, the swaging of the edges of thelaminated core provides the spaces between the paper layers forreceiving the hardening lacquer, and further in their outwardlyturnedposition. Thus, the flowing of the lacquer or resin itself into thespaces provides the permanent lock against outward movement of theflanges l I, while at the same time a thin layer of lacquer on the outersurface of the core between the flanges serves to prevent inwardmovement of the flanges prior to the coil winding operation, sincerelatively small stress in this direction is experienced.

In the operation of forming the structures, the tape windings on themandrel are carried on quickly to form long tubes, which in turn are cutinto short lengths. The flanges are slipped on to the core, the ends areswaged, and the form is dipped and then dried in an oven. The

their desired product is then complete.

It will be noted that in the foregoing construc tion, the outer surfaceof the spool is flush, the recess of the flange receiving the swagedends of the core. 'With this structure, the spool or bobbin can bereadily inserted within a compartment with a flrm bearing against thewalls thereof. t

- In the modified structure shown in Figs. 4, 5 and 6, the core I0extends throughand beyond the central opening in the flange Il The endsof the core are swaged at H and then later covered with the hardeningcoating I8.-

In order to provide a flush outer surface, as well as to protect thecorners of the flanges H, I press outwardly portions of the flange II toform outwardly'extending bosses I9, the outer ends of the bosses lyingin a plane substantially even with the coated swaged ends l1. Thus thereis provided a smooth outer face for the flanges.

In the structure shown in Figs. '7, 8 and 9, a

circular core Ill is used and the ends thereof are substantially flushwith the outer surfaces of the flanges II. The coating 20 of lacquer orvarnish, etc., extends evenly along the outer sides of the flanges IIand the outer edge portions of the core lo In this structure, thehardening material provides a ring on each side of each flange ll tohold it in position. It will be noted.

that the outer surfaces as well as the inner surface of the flange areflat, thus providing firm anchorage means for the ends of the spool.

While in the foregoing description, I have set forth certain steps insequence and certain details of structure for the purpose ofillustration, it will be understood that considerable variation may bemade in them without departing from the spirit of my invention. I wishit to be understood that I do not desire to be limited to the exactdetails of construction shown and described, for obvious modificationswill occur to a person skilled in the art.

I claim: 1 1

1. A form for windings and the like, comprising a laminated hollow papercore, flanges carried by said core in spaced relation thereon, at leastone of said flanges being at the end of the core and being engaged by arearwardly-turned end portion thereof, the laminations of said rearsaidcore being swaged outwardly and rearwardly and being in engagement withsaid flanges, the laminations of said swaged end portions beingseparated, and a hard resinous material within the space between saidseparated laminations and adhering thereto to maintain said end portionsin the swaged position whereby the flanges are locked on the core.

3. A form for windings and the like as set forth in claim 1 wherein theflange at the end of the core is provided with outwardly-struck bossesat spaced points thereon, the outer surface of each of the bosses beingsubstantially near the plane of the end of the rearwardly turned portionof the core.

4. A form for windings and the like as set forth in claim 1 wherein thecore is of polygonal cross sectional shape and is equipped with V-shapedrecesses at the corners of the rearwardly-turned end portion thereof,said recesses being held in separated position by a hard materialreceived therein and adhering thereto.

" JOHN B. SEEVER.

